Heat the oven to 180ºC/ fan 160ºC/ gas mark 4.
Cream together the butter, sugar, marmalade and orange zest until smooth. Gradually beat in the ground almonds, followed by the egg.
Fold in the flour and baking powder, and lastly stir in the buttermilk (or sour milk).
Spoon the compote into the bottom of two greased heatproof cups before gently adding the muffin mixture. Put the cups in a shallow roasting tin, then pour enough boilng water into the tin to come halfway up the sides of the cups.
Rub together the crumble ingredients and press lightly on top of the muffin mixture.
Bake the muffins for 15-25 minutes depending on the size of your cups or until a skewer into the centre comes out clean.
The mixture will make 4 x 150ml capacity cups or 2 x 300ml cups.
You could also try Bonne Maman Cherry or Rhubarb Compote in the muffins.